1. Field of the Invention
The present invention relates generally to handover, and more particularly, to a method and apparatus for handover between content servers.
2. Description of the Related Art
To meet the demand for wireless data traffic having increased since deployment of 4G communication systems, efforts have been made to develop an improved 5G or pre-5G communication system. Therefore, the 5G or pre-5G communication system is also called a ‘Beyond 4G Network’ or a ‘Post LTE System’.
The 5G communication system is considered to be implemented in higher frequency (mmWave) bands, e.g., 60 GHz bands, so as to accomplish higher data rates. To decrease propagation loss of the radio waves and increase the transmission distance, the beamforming, massive Multiple-Input Multiple-Output (MIMO), Full Dimensional MIMO (FD-MIMO), array antenna, an analog beam forming, large scale antenna techniques are discussed in 5G communication systems.
In addition, in 5G communication systems, development for system network improvement is underway based on advanced small cells, cloud Radio Access Networks (RANs), ultra-dense networks, Device-to-Device (D2D) communication, wireless backhaul, moving network, cooperative communication, Coordinated Multi-Points (CoMP), reception-end interference cancellation and the like.
In the 5G system, Hybrid FSK and QAM Modulation (FQAM) and Sliding Window Superposition Coding (SWSC) as an Advanced Coding Modulation (ACM), and Filter Bank Multi Carrier (FBMC), Non-Orthogonal Multiple Access (NOMA), and Sparse Code Multiple Access (SCMA) as an advanced access technology have been developed.
Recently, electronic devices have been used to provide users with various forms of multimedia services. For example, after accessing an Internet Protocol (IP) based network, such as the Internet, through electronic devices, the users can be provided with, not only texts and images from a service provider, but can also be provided with various multimedia services, such as a video phone service, a multimedia messaging service, a contents service, a broadcasting service, a game service, and a chatting service.
Some electronic devices guarantee mobility, in order to provide users with the multimedia services at any location while moving. Electronic devices guaranteeing mobility in this manner are called mobile devices. For example, electronic devices, such as smart phones, tablet Personal Computers (PCs), Personal Digital Assistants (PDAs), notebooks, digital cameras, etc., have a function of wirelessly accessing an IP-based network, such as the Internet.
Meantime, when users are provided with the multimedia services through electronic devices, the users can be provided with the multimedia services only through a single accessed network. For example, some the electronic devices can access a 3rd Generation (3G) network or a 4th Generation Long Term Evolution (4G LTE) network, and receive the multimedia services from the 3G network or the 4G LTE network.
As an alternative, the electronic devices can access a Wireless Local Area Network (WLAN) such as Wireless Fidelity (WiFi), and receive the multimedia services from the WLAN. Some electronic devices can gain access to a wireless network, such as Worldwide Interoperability for Microwave Access (WiMax), and receive the multimedia services from the wireless network.
Electronic devices can access a Content Delivery Network (CDN), and download contents from the CDN. A CDN is a network for efficiently delivering contents in order to offload traffic from an Internet backbone network or provide a fast response time to an electronic device.
An electronic device can create a session with a content server, and can download contents from the content server while performing handover from a legacy Base Station (BS) (i.e., an Access Router (AR)) to a new BS. To prevent a data loss and disconnection of the session for contents downloading during the handover, an IP address of the electronic device must be maintained without being changed. Herein, a BS can correspond to any access nodes having a gateway function. The following example assumes that the BS represents an access router of the Internet Engineering Task Force Distributed Mobility Management Working Group (IETF DMM WG), but the BS can be also a Local Gateway (LGW) of 3rd Generation Partnership Project (3GPP).
If a Proxy Mobile Internet Protocol (PMIP) is used, when an electronic device moves to a new BS, the new BS, in place of the electronic device, sends a Proxy Binding Update (PBU) message to a legacy BS and notifies the legacy BS of a location of the electronic device.
In a response to the received PBU message, the legacy BS sends a Proxy Binding Acknowledgement (PBA) message to the new BS, thereby creating a tunnel between the legacy BS and the new BS.
Packets destined from the content server to the electronic device are forwarded from the legacy BS to the new BS through a tunnel created between the legacy BS and the new BS. The packets are again forwarded from the new BS to the electronic device.
Accordingly, though performing handover, the electronic device can still maintain a legacy session and continuously download contents. More specifically, when the electronic device performs a handover, packet transmission is achieved through the tunnel created between the BSs in order to maintain a continuity of the legacy session.
If a new content server closer to the new BS exists, it is possible to setup a closer transmission path than a transmission path of forwarding the packets through the tunnel between the BSs.
However, because the present time maintains the legacy session as it is after the handover, it is impossible to perform contents downloading using the new content server and the closer transmission path.